Payback Lab

How long until this purchase pays for itself?

For long-termists and deliberate buyers: one calm suite of calculators that compare a one-time purchase against the recurring spend it replaces.

Same math everywhere — months to break even, monthly savings, financing, lifetime net. Private: numbers stay in your browser.

Buy once. Track the payback. Pick a tool below — coffee, kitchen appliances, sparkling water, filters, and more. Adjust presets to your habits; results update instantly.

Calculators

Kitchen & drinks

This cluster shares the same shell and formula: replace a recurring bill (café, takeout, bottles, bakery) with a home setup, then see when the purchase is recovered.

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Want another “pays for itself” tool? Placeholder for later Formspree / Tally / GitHub Issues.

Disclaimer: All calculators are for education and estimates only. They are not financial advice. 本站计算仅为估算与教育用途，不构成财务、投资或消费建议。